Prep Essential: Purify Your Own Water

Today I saw a post on a Facebook camping/survival site with a lot of dubious information being shared on how to get clean drinking water. Dubious information on drinking water leads to sick people. In response, I decided to share this excerpt on water purification from my e-book, The Truth About Simple Unhooked Living. This is not offered as the last word, but as a solid point from which people can continue their investigations. Anybody relying on surface water for drinking must perform due diligence in devising their plans.

Personal Water Filters

I never had to filter my household’s water until moving into a place served by a municipal water supply. The city circulated a notice that said its water contained several heavy metals at levels higher than officially recommended. I decided to try filtering them out with my Mini-Works, a personal camping size unit made by Mountain Safety Research (MSRR). The literature says the Mini-Works filters out bacteria and protozoa, including giardia and cryptosporidia, as well as many chemicals, including pesticides and iodine, and it will trap pathogens attached to particles .3 microns and larger. It cannot be said to be 100 percent effective against all bugs, some of which may be as small as .05 microns. Neither can ceramic filters be expected to remove all chemicals or any radioactive contamination.

Look for a Water Filter with Impregnated Silver

Another popular personal water filter is the Ceradyn, approved by the US government and reportedly used by NATO, International Red Cross, and Wycliffe Bible Translators. The .2-micron ceramic filter is designed to remove microorganisms, bacteria, parasites, algae, and cysts. It also protects against typhoid, dysentery, cholera, and giardiasis, otherwise known as traveler’s diarrhea. Tiny silver granules are hermetically sealed in the filter to prevent the growth of bacteria and mold. The Ceradyn accommodates filters that remove bacteria only from up to 13,000 gallons of water, and those with carbon, which also remove chemicals and foul odors.

Watch Out for the Feces

Giardia and cryptosporidia are one-celled parasites found in the feces of infected animals and humans. They are spread through contaminated food and water. An attack of giardia results in diarrhea, stomach cramps, bloating, gas, fatigue and weight loss. The symptoms can last for weeks. Infected persons may experience no symptoms, yet they may be contagious for months. Cryptosporidia feels much like the flu, with stomach cramps, headaches, nausea, vomiting and a low-grade fever. Water filter labels should state their effectiveness against these pathogens

Inquire with the National Sanitation Foundation, an independent non-profit testing group, to find out what pathogens are removed by various filters. Their website provides a searchable database of NSF-certified companies and their products. If you have questions about whether a product is NSF certified, or about how to interpret the data, you can call them at 800-673-6275.

Can Bleach and Iodine Purify Water?

So what does one do about the little bugs that are too small to get caught in the filters? Some people kill them with iodine. Iodine drops or tablets can be put in water for thirty minutes, then run through a ceramic filter to remove taste and odor. Iodine has long been used to purify water, but it can’t be assumed that it alone will do the trick. According to NSF International, iodine will not kill cysts. Boiling, or running the water through a filter certified for cyst reduction, is still necessary. Also, the body uses iodine for metabolism and proper thyroid functioning, but it’s not a good idea for everyone to ingest it. Better check with a doctor if considering iodine as part of a water purification regime.

How About a Shot of Chlorine Dioxide?

Some people prefer chlorine dioxide, saying it is more effective and tastes better than iodine. Chlorine dioxide is a potent oxidizing agent with many industrial uses such as cleaning water in municipal systems, bleaching flour and paper pulp, and sterilizing medical equipment. Chlorine dioxide is not the same as household chlorine bleach. There are many pathogens household bleach will not kill, so it can’t be relied on to purify drinking water. However, in emergency situations, when it’s the only thing available, the Red Cross says to add 16 drops of bleach that contains a hypochlorite solution of at least 5.25 percent to a gallon of water, and let it stand for at least 30 minutes.

Countertop Water Filters

Something larger than a personal water filter is more practical for everyday use. Here are some straightforward methods of purifying the household water supply in the unhooked home. Doulton makes a highly respected stainless steel countertop gravity flow filtering system that cleans up to 30,000 gallons of water with one set of filters. They also make a larger counter top model that can purify sufficient drinking water for 160 people a day, and a small backpack-sized unit.

Here’s how they work. Contaminated water is poured into the upper container, then it slowly trickles through porous ceramic filters to a collection chamber below. Doulton filters (also called “candles”) are made from diatomaceous earth, silver, and carbon. The outer layer of diatomaceous earth is comprised of fossilized microscopic silicon shells covered with tiny holes. Bacteria are trapped in the holes and neutralized by silver impregnated within the ceramic wall. A carbon mixture inside the filter reduces bad tastes, pesticides, herbicides, and heavy metals, such as lead and aluminum. Doulton filters trap 99.99 percent of giardia, cryptosporidium, E coli, vibroe cholerae, salmonella, and disinteria.

There are several tabletop gravity flow ceramic filter systems that work on the same principle. Another popular brand is The Berkey Light, used by UNICEF, Peace Corps, Red Cross, and other relief agencies in 140 countries. It filters out e-coli, cholera, salmonella, typhi, giardia, cryptosporidium, chlorine, bleach, and rust. Both the upper and lower chambers of this brand are made of transparent Lexan, a material used in bulletproof glass. The clear case enables users to check the progress of the water in the chambers at any time.

The effectiveness of these systems is enhanced, and the filters will last longer, when dirt and debris are strained out through a clean cloth before treatment. Moreover, as a layer of grime forms on the outside of the ceramic wall, the surface should be gently scrubbed with a brush. This process can be repeated several hundred times before the ceramic material is exhausted.

Ceramic replacement filters for gravity flow systems cost up to $50 each and some units require four or more elements. It is an expense that needs to be factored in. But even so, it’s hard to beat the cost of purifying water with ceramic gravity flow filters, which can clean five gallons for about a penny. If everybody who buys bottled water used one of these units, a big dent could be made in the mountains of plastic containers accumulating around the planet. A lot of people are figuring out that ceramic filter systems are good to have, so online stores that carry them are often sold out. If you want one you may have to get on a waiting list.

Distilling Water on the Stove

Distillation is an effective way to purify water. Pre-filtered water is heated to boiling in one chamber and the resulting vapor is directed through a tube to a receptacle where it cools and condenses back into liquid. Most pathogens are destroyed during the boiling phase, and most impurities are left behind or driven off as gases. Distilling is not necessarily useful at removing all volatile compounds, such as pesticides and herbicides, because they can evaporate and move into the second chamber along with the steam. Most distillers run on electricity, but Water Wise makes a model that works on a woodstove, propane grill, campfire, or any source of heat. It produces up to 16 gallons a day of pure water. This is a decent solution during winter, when the woodstove is already going all day.

ClearDome Solar, LLC, of San Diego offers the Water Still and Pasteurizer, capable of distilling most foul water into delicious, 99 percent pure drinking water with only 0 to 4 parts per million of impurities remaining. It purifies five cups of water in about 2 1/2 hours on any stove. Water boils and becomes steam, which passes through a short food-safe copper tube, and into a heat resistant container where the vapor cools and condenses back into fresh water. Gases like chlorine can escape through a small opening between the two containers. The components are essentially a three-quart stainless steel kettle with a copper bottom, a food-safe NSF certified copper tube, and a three-gallon BPA-free plastic re-condensing/storage container. You can check with ClearDome to see if they will sell you just the tube, then you can gather the other parts yourself and save money. They have a lot of information online about this distiller and their other products.

Distilling Water With the Sun

ClearDome Solar has also developed the Dome Solar Still water purifier/pasteurizer, which accomplishes water purification with only the heat of the sun. Water to be distilled is poured into a dispenser and gravity fed through the system. This produces about two gallons of fresh water on a good day. Total dissolved solids in the finished product average 0-3 parts per million, while tap water ordinarily ranges from 350-600.

Boiling and Pasteurizing Water

Experts agree that boiling water kills many harmful microorganisms, including most bacteria, cysts, and viruses. The recommended boiling time varies from one to ten minutes, depending on the expert in question. Some say that by the time water reaches a rolling boil it has already done its job. A ten-minute rolling boil was the rule of thumb in the old days and many health departments still recommend that length of time when public systems fail. However, the Centers for Disease Control and Prevention now recommend a three-minute rolling boil. This may seem like splitting hairs, but boiling time becomes a critical factor whenever fuel is scarce.

Boiling Requires and Abundance of Fuel

In developing nations, where waterborne illness is a huge problem, people resist purifying water by the tried and true method of boiling. That’s because it requires too much fuel, which is extremely hard to come by in arid, drought-ridden places. In some areas women must routinely walk for an entire day just to reach a source of firewood for cooking. They spend another day collecting the wood, and a third day hauling it home. This time-consuming quest for fuel is a non-issue most of the time in developed nations, but in the event of a catastrophe, fuel may become hard to get.

Pasteurizing Water Like Milk?

In 1983, David Ciochetti conducted a series of tests from which he concluded that heating water to 149 degrees Fahrenheit for 15 minutes kills disease-causing microbes, including germs, viruses, and parasites. This process is called pasteurization and cuts fuel use by about half over the boiling method. Other scientists have verified his research since then. It has been found that filtering and aerating water before pasteurizing makes the process more effective.

Water can be pasteurized in a black container set into a solar box cooker placed in a sunny location. The black container can be covered with a plastic cooking bag to retain more heat. Some studies favor using glass bottles in the solar cooker, so the water can be exposed to the sun’s beneficial ultraviolet rays. Another idea is to use clear glass and place flat black material behind it to help draw in more of the sun’s heat. It is important to monitor the water temperature with a thermometer to ensure the temperature required to kill bacteria is maintained.